changing date change time within single excel 365

[Coolkinkster0001]

Attempting to set-up a 24 hour calendar that will have the date change at 10:00 A.M. rather than at 12:00 A.M.

Unable to figure out a formula for this to happen without changing the date/time on the computer. There must be a formula that this old men can't figure out.

[#2]

@Coolkinkster0001 

If change both date and time that could be like